Backlit displays using graphics (e.g. images, alphanumeric text, other indicia and combinations thereof) displayed on a sheet or web positioned over an illumination source are known for advertising and other information-conveying or display purposes.
Some such displays employ a single fixed and stationary image, while others employ a scrolling configuration in which multiple graphic displays or frames are presented on a flexible web or sheet entrained about a set of rollers, whereby manual or powered rotation of the rollers can be used to change which graphic display or frame is displayed in the span of the web or sheet between the rollers.
Examples of stationary image backlit displays can be found in U.S. Pat. No. 7,220,019 and U.S. Patent Application Publications 2004/0004827 2006/0107568. Scrolling image backlit displays can be found in U.S. Pat. No. 5,412,892 U.S. Patent Application Publications 2010/0107461.
In the forgoing prior art, even where a scrolling web is used to allow display of different graphics at different times without swapping out the display sheet or web, they can only be display one at a time. Thus, the only way to display two different graphics that share common backdrop or background elements is to print the two such graphics on the same web, and have the device scroll from one graphic to the other. Also, of the above references, only U.S. Pat. No. 7,220,019 uses color LED's to illuminate the display, and provides limited description of possible color effects achievable by same.
U.S. Pat. Nos. 4,104,810 and 4,434,568 teach scrolling displays that employ multiple scrolling elements to allow variation of the graphic display by superimposing elements of one scrolling element over an underlying scrolling element. The displays are not backlit and thus cannot provide the same vibrant effect as a backlit display, and the particular scroll configurations shown are not suitable for mere addition of a backlight device according to conventional backlit displays.
Display devices of other types less relevant to the present invention are also known, for example including displays that employ lenticular lenses to create the appearance of a changing image, as disclosed in U.S. Pat. No. 5,695,346 and Canadian Patent Applications 2284405 and 2312683. However, such prior art provides no hint of how to address the aforementioned shortcomings of the prior art in for scrolling, backlit displays.
Accordingly, there remains room for improvement in the field of scrolling and backlit displays.